From a0eb20ff1f27d62e02d27876f25f8f5fbf5690c5 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 3 May 2019 14:29:36 -0400
Subject: [PATCH] Tweaks divide-by-zero timing.

---
 .../Implementation/68000Implementation.hpp    | 24 +++++++++++--------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/Processors/68000/Implementation/68000Implementation.hpp b/Processors/68000/Implementation/68000Implementation.hpp
index 678302fe9..2244a524d 100644
--- a/Processors/68000/Implementation/68000Implementation.hpp
+++ b/Processors/68000/Implementation/68000Implementation.hpp
@@ -884,15 +884,21 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
 									Divisions.
 								*/
 
+#define announce_divide_by_zero()						\
+	active_program_ = nullptr;							\
+	active_micro_op_ = short_exception_micro_ops_;		\
+	bus_program = active_micro_op_->bus_program;		\
+														\
+	populate_trap_steps(5, get_status());				\
+	bus_program->microcycle.length = HalfCycles(8);		\
+														\
+	program_counter_.full -= 2;
+
 								case Operation::DIVU: {
 									// An attempt to divide by zero schedules an exception.
 									if(!active_program_->source->halves.low.full) {
 										// Schedule a divide-by-zero exception.
-										active_program_ = nullptr;
-										active_micro_op_ = short_exception_micro_ops_;
-										bus_program = active_micro_op_->bus_program;
-										populate_trap_steps(5, get_status());
-										program_counter_.full -= 2;
+										announce_divide_by_zero();
 										break;
 									}
 
@@ -951,11 +957,7 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
 									// An attempt to divide by zero schedules an exception.
 									if(!active_program_->source->halves.low.full) {
 										// Schedule a divide-by-zero exception.
-										active_program_ = nullptr;
-										active_micro_op_ = short_exception_micro_ops_;
-										bus_program = active_micro_op_->bus_program;
-										populate_trap_steps(5, get_status());
-										program_counter_.full -= 2;
+										announce_divide_by_zero()
 										break;
 									}
 
@@ -1005,6 +1007,8 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
 									active_step_->microcycle.length = HalfCycles(cycles_expended * 2);
 								} break;
 
+#undef announce_divide_by_zero
+
 								/*
 									MOVEP: move words and long-words a byte at a time.
 								*/